Docker in Practice

370 Pages·2016·6.35 MB·English

P
IN RACTICE

Ian Miell
Aidan Hobson Sayers
F Ben Firshman
OREWORD BY
M A N N I N G
Docker in Practice

Docker in Practice
IAN MIELL
AIDAN HOBSON SAYERS
MANNING
SHELTER ISLAND
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ISBN 9781617292729
Printed in the United States of America
1 2 3 4 5 6 7 8 9 10 – EBM – 21 20 19 18 17 16
brief contents
P 1 D ....................................................1
ART OCKER FUNDAMENTALS
1 ■ Discovering Docker 3
2 ■ Understanding Docker—inside the engine room 19
P 2 D .............................................41
ART OCKER AND DEVELOPMENT
3 ■ Using Docker as a lightweight virtual machine 43
4 ■ Day-to-day Docker 65
5 ■ Configuration management—getting your house in
order 103
P 3 D D O ...................................................143
ART OCKER AND EV PS
6 ■ Continuous integration: speeding up your development
pipeline 145
7 ■ Continuous delivery: a perfect fit for Docker
principles 169
8 ■ Network simulation: realistic environment testing without
the pain 186
v
vi BRIEF CONTENTS
P 4 D ...............................................213
ART OCKER IN PRODUCTION
9 ■ Container orchestration: managing multiple Docker
containers 215
10 ■ Docker and security 262
11 ■ Plain sailing—Docker in production and operational
considerations 291
12 ■ Docker in production—dealing with challenges 308
contents
foreword xv
preface xvii
acknowledgments xix
about this book xx
about the cover illustration xxiii
P 1 D ........................................1
ART OCKER FUNDAMENTALS
1 Discovering Docker 3
1.1 The what and why of Docker 5
What is Docker? 5 ■ What is Docker good for? 7 ■ Key
concepts 8
1.2 Building a Docker application 10
Ways to create a new Docker image 11 ■ Writing a Dockerfile 12
Building a Docker image 13 ■ Running a Docker container 14
Docker layering 16
1.3 Summary 18
2 Understanding Docker—inside the engine room 19
2.1 Docker’s architecture 20
vii
viii CONTENTS
2.2 The Docker daemon 21
TECHNIQUE 1 Open your Docker daemon to the world 22
TECHNIQUE 2 Running containers as daemons 23
TECHNIQUE 3 Moving Docker to a different partition 26
2.3 The Docker client 27
TECHNIQUE 4 Use socat to monitor Docker API traffic 27
TECHNIQUE 5 Using ports to connect to containers 29
TECHNIQUE 6 Linking containers for port isolation 31
TECHNIQUE 7 Using Docker in your browser 33
2.4 Docker registries 34
TECHNIQUE 8 Setting up a local Docker registry 35
2.5 The Docker Hub 36
TECHNIQUE 9 Finding and running a Docker image 37
2.6 Summary 39
P 2 D .................................41
ART OCKER AND DEVELOPMENT
3 Using Docker as a lightweight virtual machine 43
3.1 From VM to container 44
TECHNIQUE 10 Converting your VM to a container 44
TECHNIQUE 11 A host-like container 47
TECHNIQUE 12 Splitting a system into microservice containers 49
3.2 Managing services on your containers 52
TECHNIQUE 13 Managing the startup of your container’s
services 53
3.3 Saving and restoring your work 55
TECHNIQUE 14 The “save game” approach to development 55
TECHNIQUE 15 Docker tagging 57
TECHNIQUE 16 Sharing images on the Docker Hub 59
TECHNIQUE 17 Referring to a specific image in builds 61
3.4 Environments as processes 62
TECHNIQUE 18 The “save game” approach to development 62
3.5 Summary 64
4 Day-to-day Docker 65
4.1 Volumes—a persistent problem 66
TECHNIQUE 19 Docker volumes—problems of persistence 66
TECHNIQUE 20 Distributed volumes with BitTorrent Sync 67
CONTENTS ix
TECHNIQUE 21 Retain your container’s bash history 69
TECHNIQUE 22 Data containers 71
TECHNIQUE 23 Remote volume mounting using sshfs 74
TECHNIQUE 24 Sharing data over NFS 76
TECHNIQUE 25 Dev tools container 78
4.2 Running containers 79
TECHNIQUE 26 Running GUIs within Docker 79
TECHNIQUE 27 Inspecting containers 81
TECHNIQUE 28 Cleanly killing containers 83
TECHNIQUE 29 Using Docker Machine to provision Docker
hosts 84
4.3 Building images 87
TECHNIQUE 30 Injecting files into your image using ADD 88
TECHNIQUE 31 Rebuilding without the cache 90
TECHNIQUE 32 Busting the cache 92
4.4 Staying ship-shape 93
TECHNIQUE 33 Running Docker without sudo 93
TECHNIQUE 34 Housekeeping containers 94
TECHNIQUE 35 Housekeeping volumes 95
TECHNIQUE 36 Detaching containers without stopping them 97
TECHNIQUE 37 Using DockerUI to manage your Docker
daemon 98
TECHNIQUE 38 Generate a dependency graph of your Docker
images 99
TECHNIQUE 39 Direct action—execute commands on your
container 101
4.5 Summary 102
5 Configuration management—getting your house in order 103
5.1 Configuration management and Dockerfiles 104
TECHNIQUE 40 Create reliable bespoke tools with
ENTRYPOINT 104
TECHNIQUE 41 Avoid package drift by specifying versions in your
build 106
TECHNIQUE 42 Replacing text with perl -p -i -e 107
TECHNIQUE 43 Flattening images 109
TECHNIQUE 44 Managing foreign packages with alien 111
TECHNIQUE 45 Reverse-engineer a Dockerfile from an
image 113
5.2 Traditional configuration management tools with
Docker 116
TECHNIQUE 46 Traditional: using make with Docker 116